1. Field of Invention
This invention relates to the field of construction of filter units for home aquariums.
2. Description of the Prior Art
Cleaning or other servicing of an aquarium filter ordinarily involves removal of the various component parts of the filter such as the motor, the pump and the filter material from the aquarium, and for convenience, the motor must usually be disconnected from the power socket. The present invention greatly simplifies such chores, thereby encouraging their performance more often, with the result that the cleanliness of the aquarium water is more easily maintained.
The use of magnetic coupling to transmit power is not novel. Such devices have been used in automobile speedometers, lunch counter juice dispensers and other devices as shown in the following U.S. Pat. Nos. Jacobs, Nos. 2,745,641 and 3,119,531; Mould, 3,045,134; Rankin, 2,638,588; Fay 591,395; Cassassa, 2,951,447; Schug, 2,366,562; Akulitch, 2,669,668; Baratz, 3,172,464; and Tabor, 1,982,971. Magnetic coupling has also been used in aquarium pumping and filtering devices as shown by Canterbury U.S. Pat. No. 3,273,717, and Willinger, U.S. Pat. Nos. 3,392,836; 3,512,646 and 3,321,081.
The Jacobs and Mould patents dealt with pumping fruit juices and similar beverages; Rankin involved deep well pumps and power transmission arrangements; Fay and Cassassa referred to gas and fuel pumps; Schug shows a refrigeration unit; Akulitch shows such a device used in chemical and dairy pumps, and Baratz and Tabor dealt with centrifugal pumps generally.
Similarly, the use of an open tank, raising water by siphon, filtration by charcoal or activated carbon and employing gravity for filtration are in common use.
A device manufactured by the Ralph Hagen U.S.A. Corporation some years ago is also pertinent. This device was the subject of the case of Metaframe Corp. v. Biozonics Corp., 176 U.S.P.Q. 237.
Only those above devices dealing with aquarium filters and pumps will be discussed below.
The device of Canterbury U.S. Pat. No. 3,273,717 employs a sealed cylindrical filtration receptacle supported from the rim of one side of an aquarium, inside the filtration receptacle is located a hollow cylindrical filter. The aquarium water is passed through the walls of this cylindrical filter for removal of particles. Further, in one embodiment of the device of Canterbury, the motor unit is supported by the filter receptacle such that the filter receptacle cannot be removed from the aquarium without also removing the motor unit. In another embodiment, the motor unit is provided with legs and stands on a firm footing in an independent housing designed to accept the lower end of the filter receptacle (See FIG. 7 of Canterbury patent). The advantages of the present invention over the device of Canterbury will become apparent later in this specification.
In Willinger U.S. Pat. No. 3,321,081 is disclosed an aquarium filtration system similar to the present invention, however, in Willinger as in Canterbury, the motor unit is mounted upon and supported by the filtration receptacle. Also in Willinger U.S. Pat. No. 3,321,081, the tube which returns the clean water to the aquarium is not located in a recess in the side of the filtration receptacle and would interfere somewhat with convenient cleaning or changing of the filter material. These same comments apply to Willinger U.S. Pat. Nos. 3,512,646 and 3,392,836. Moreover, the claims of the U.S. Pat. No. 3,512,646 device are directed to the rotor device (claim 1) and a bearing means comprising a ball and other items (claim 2); and the claim of the U.S. Pat. No. 3,392,836 device is directed to a heat transfer relationship between the water and pump motor unit.
The advantages and improvements of the present invention over these prior art devices will become apparent from an inspection of the accompanying drawings and description.